학술논문

Temperature-Dependent Optical Behaviors and Demonstration of Carrier Localization in Polar and Semipolar AlGaN Multiple Quantum Wells
Document Type
article
Source
Crystals, Vol 13, Iss 7, p 1076 (2023)
Subject
AlGaN MQWs
ultraviolet emitters
carrier localization
Crystallography
QD901-999
Language
English
ISSN
13071076
2073-4352
Abstract
Semipolar AlGaN multiple quantum wells (MQWs) have unique advantages in deep ultraviolet light emitters due to the weak Quantum-Confined Stark Effect. However, their applications are hampered by the poor crystalline quality of semipolar AlGaN thin films. Different treatments were developed to improve the crystal quality of semipolar AlGaN, including a multistep in situ thermal annealing technique proposed by our group. In this work, temperature-dependent and time-resolved photoluminescence characterizations were performed to reveal the carrier localization in the MQW region. The degree of carrier localization in semipolar AlGaN MQWs grown on top of the in situ-annealed AlN is similar to that of conventional ex situ face-to-face annealing, both of which are significantly stronger than that of the c-plane counterpart. Moreover, MQWs on in situ-annealed AlN show drastically reduced dislocation densities, demonstrating its great potential for the future development of high-efficiency optoelectronic devices.